Australian PM John Howard has denied involvement in a decision to ban a graphic that tracks audience opinion during a live TV election debate.
John Howard is seeking election to a fifth term after 11 years in power.
Critics accused Mr Howard of coercing the host, the National Press Club, to ban the use of the "worm".
Channel Nine's feed was cut 25 minutes into the debate between Mr Howard and the opposition leader Kevin Rudd.
The controversy has eclipsed the issues under discussion, which included the economy and Australia's role in Iraq.
The Channel Nine worm charts the changing opinions of 90 undecided voters in the upcoming November elections.
It turns white and climbs up the screen if the audience reaction is positive, but turns red and burrows down when the voters have a negative reaction.
Mr Howard has fared badly against the worm in previous debates, and has argued that its presence trivialises politics and distracts from the issues being debated.
But the National Press Club of Australia, which hosted the debate and provided Channel Nine's feed, denied that it was reacting to pressure from Mr Howard in imposing a ban on the worm graphic.
In a statement on their website, the NPC said that there had been no interference from either political party and insisted that Channel Nine had agreed to the conditions beforehand.
It said that Nine was free to use the worm as long as it used a delayed feed, and so by broadcasting the worm live it breached rules.
Veteran Channel Nine presenter Ray Martin has accused the NPC and Mr Howard's office of attempting to stifle the media.
"This is not John Howard's election or Kevin Rudd's election," he said. "This is the Australian voter's election."
"John Howard can't tell us how to hold a debate," he added.
Channel Nine switched first to an ABC and then a Sky News feed, and superimposed the worm without any disruption to its coverage.
According to the worm, Mr Rudd was the overall winner of the debate. Opinion in Australia is divided on whether the worm really has any impact on voters.